Fly-casting is an artful form of fishing that has proven popular through the years. One goal of the fly casting stroke is to deliver a weightless fly to a targeted location or fish. The proper fly-casting stroke involves the transfer of energy from the loaded (bent) fly rod to the fly line, causing the line to form a loop that will then pass through the air to deliver the fly to the desired location. To transfer this energy; the fly caster accelerates the fly rod through the casting stroke and then, stops the rod so that the energy from the bent rod transfers to the fly line causing it to form a loop and fly through the air. There is a forward cast and a back cast as the fly rod is moved back and forth. The caster must learn to wait while the line unrolls behind him on his back cast before accelerating the fly rod into the forward stroke.
There is also a casting method known as the double haul that is used to add line speed to the casting stroke and thus add distance to the fly cast. To accomplish the double haul, the caster pulls down on the fly line in both the forward and backward casting stroke, causing more bend or load in the fly rod to thereby increase the energy that can be transferred to the fly line. The caster then releases the fly line, causing the fly to travel a longer distance. Since the fly line is essentially weightless and cannot be thrown, the fly caster must master the components of a good fly casting stroke in order to deliver the fly to the desired location. The components of a fly casting stroke include, among other things, making a smooth acceleration to a positive controlled stop, in both the forward and back cast, with proper timing and speed. Performing the double haul requires the additional coordination of the fly rod stroke with the timing and speed of pulling and releasing the fly line to load and release the fly rod for extra distance of the fly cast.
There have been prior attempts to develop aids for fly-casting. For example, U.S. Pat. No. 6,763,628 discloses a handle that can be attached to a fly rod. The handle provides a means for an instructor to grip the fly rod in concert with a fly casting student in order for the instructor to impart his muscle memory of the casting stroke to the student. This might be useful during a fly-casting lesson with an instructor. However, a training device that the student can take home, use indoors or outdoors, and in winter or summer, would add significant training time for a fly casting student to develop the proper muscle memory for a good fly-casting stroke. In addition, the casting stroke must be adjusted to accomplish casting different lengths of line. A short casting stroke is used to cast a short length of fly line and a longer casting stroke is used to cast greater distances. With an adjustable multi-sensory fly casting trainer, the student can adjust the fly casting trainer apparatus to practice the casting stroke for various lengths of line.
The double haul is an advanced fly-casting technique employed to add line speed so that greater lengths of line can be cast. It is often necessary to cast greater lengths of line when fishing large bodies of water such as wide rivers, lakes and the ocean. The timing and smoothness of a well-formed double haul cast are, therefore, beneficial for a fly fisherman to learn.